1. Field of the Invention
The present invention relates to a display, a mobile device, and a method of manufacturing the display, and more particularly, to a display that has a display panel, a mobile device that includes the display, and a method of manufacturing the display.
2. Cross-Reference To Related Applications
The priority applications Nos. JP2004-342980 and JP2004-345876 upon which this patent application is based are hereby incorporated by reference.
3. Description of the Background Art
An example of a conventional display having a display panel is disclosed in Japanese Patent Publication No. 3322629. More specifically, Japanese Patent Publication No. 3322629 discloses a liquid crystal display unit that has a flexible printed circuit board at the peripheral portion of a glass substrate (a display panel) disposed inside a front case and a rear case. The flexible printed circuit board extends outward through the openings of the front case and the rear case, with the height of the flexible printed circuit board being the same as the height of the portion at which the flexible printed circuit board is attached to the glass substrate.
Conventionally, LCD units having small-sized display panels to be used for mobile phone handsets have been known. FIG. 20 is a perspective view of a conventional LCD unit that has a display panel to be used for a mobile phone handset. FIG. 21 is a perspective cross-sectional view of the LCD unit, taken along the line 300-300 of FIG. 20. FIG. 22 is a cross-sectional view illustrating a situation in which the conventional LCD unit shown in FIG. 20 is disposed inside a mobile phone handset. FIG. 23 is an exploded perspective view of the conventional LCD unit shown in FIG. 20. Referring to FIGS. 20 through 23, the structure of the conventional LCD unit 120 is described.
As shown in FIG. 20, the conventional LCD unit 120 includes an upper frame 101 and a lower frame 102 that are made of metal, an upper deflecting plate 103 that is disposed inside the upper frame 101 and the lower frame 102, and a panel flexible printed circuit board (a panel FPC board) 104 having a thickness of approximately 0.2 mm.
As shown in FIG. 23, the lower frame 102a includes a bottom face portion 102a and four side face portions 102b that extend upward from the four sides of the bottom face portion 102a. The side face portions 102b have protruding portions 102c protruding outward. A notch portion 102d is formed in the side face portion 102b on the side to which the panel FPC board 104 is to be attached. Further, a reflective sheet 105 is disposed above the bottom face portion 102a of the lower frame 102. A resin frame 106 having an opening 106a at the bottom is provided above the reflective sheet 105. In the resin frame 106, a FPC inserting portion 106b through which the panel FPC board 104 is to be inserted is formed at the location corresponding to the notch portion 102d of the lower frame 102. The resin frame 106 also has concave portions 106c at the portion of the opening 106a on the side of the FPC inserting portion 106b of the resin frame 106.
Inside the resin frame 106, a light guide plate 108 for guiding the light from light emitting diodes (LEDs) 107 (see FIGS. 21 and 22) to the entire panel, and two lens sheets 109 are stacked in this order from the bottom, as shown in FIGS. 21 through 23. As shown in FIGS. 21 and 22, the light guide plate 108 has a side face 108a through which the light from the LEDs 107 enters. The lens sheets 109 transmit light upward from the light guide plate 108, and also concentrate the light. A diffusion sheet 110 is provided above the lens sheets 109. This diffusion sheet 110 transmits light upward from the lens sheets 109, and also diffuses the light. With two-sided tape (not shown), a backlight flexible printed circuit board (a backlight FPC board) 111 is bonded to the upper side of the light guide plate 108 through which the light from the LEDs 107 enters. The backlight FPC board 111 has an external connecting portion that protrudes outward from the FPC inserting portion 106b of the resin frame 106. A connector inserting portion 111a (see FIG. 23) is formed at the top end portion of the external connecting portion. The backlight FPC board 111 also has the LEDs 107 that function as backlight sources, as shown in FIGS. 21 and 22. The LEDs 107 are accommodated by the concave portions 106c of the resin frame 106. The LEDs 107 are disposed in such a manner as to emit light toward the light guide plate 108. As shown in FIG. 23, an adhesive layer 112 having an opening 112a is bonded to the peripheral portion of the upper face of the diffusion sheet 110. As shown in FIGS. 21 through 23, a lower deflecting plate 113 is disposed above the adhesive layer 112. Further, a lower glass substrate 114 and an upper glass substrate 115 that are arranged to interpose liquid crystal are provided above the lower deflecting plate 113. Although not shown, a thin-film transistor is formed on the lower glass substrate 114. The glass substrates 114 and 115 including the liquid crystal and the thin-film transistor constitute a display panel. The lower glass substrate 114 has a protruding portion 114a protruding from the lower deflecting plate 113 and the upper glass substrate 115 toward the concave portions 106c of the resin frame 106. The upper deflecting plate 103 is further disposed on the region corresponding to the display region of the glass substrates 114 and 115.
Further, a driver IC (integrated circuit) 116 for driving the display panel and the panel FPC board 104 are mounted onto the upper face of the protruding portion 114a of the lower glass substrate 114. The panel FPC board 104 is electrically connected to the driver IC 116. The panel FPC board 104 is also disposed to protrude outward from the FPC inserting portion 106b of the resin frame 106 and the notch portion 102d of the lower frame 102.
As shown in FIG. 20, an electronic component attaching portion 104a to which electronic components 117 are to be attached is formed at the outward protruding portion of the panel FPC board 104. A connector portion 118 to which the connector inserting portion 111a (see FIG. 23) of the backlight FPC board 111 is to be connected is also attached to the electronic component attaching portion 104a. Further, the connector inserting portion 104b is formed at the end of the electronic component attaching portion 104a. As shown in FIG. 22, the connector inserting portion 104b is connected to a connector portion 131 of the printed circuit board 130 of a mobile phone handset. The printed circuit board 130 is disposed inside an upper chassis 150 and a lower chassis 151 of the mobile phone handset.
As shown in FIGS. 21 through 23, the metal upper frame 101 is disposed above the upper deflecting plate 103. The upper frame 101 includes an upper face portion 101b having an opening 101a, and four side face portions 101c that extend downward from the four sides of the upper face portion 101b. The opening 101a of the upper frame 101 is formed in the area corresponding to the display region of the glass substrates 114 and 115. Further, as shown in FIG. 23, insertion holes 101d through which protruding portions 102c of the lower frame 102 are to be inserted are formed in the side face portions 101c of the upper frame 101. A notch portion 101e is also formed at the location of the side face portion 101c corresponding to the notch portion 102d of the lower frame 102. By virtue of the opening formed with the notch portion 102d of the lower frame 102 and the notch portion 101e of the upper frame 101, the panel FPC board 104 and the backlight FPC board 111 are designed to protrude outward, as shown in FIG. 20.
In the conventional LCD unit 120 illustrated in FIGS. 20 through 23, the panel FPC board 104 attached onto the upper face of the protruding portion 114a of the glass substrate 114 extends to the outside of the upper frame 101 and the lower frame 102, without touching the upper frame 101 and the lower frame 102. Accordingly, the panel FPC board 104 protrudes outside the upper frame 101 and the lower frame 102, at the same height as the protruding portion 114a of the glass substrate 114. As shown in FIG. 22, when the LCD unit 120 is housed in a mobile phone handset including the upper chassis 150 having the inner face portion protruding downward, the electronic components 117 mounted onto the upper face of the panel FPC board 104 are easily brought into contact with the inner face of the upper chassis 150. As a result, the electronic components 117 are often damaged, causing the problem of defective display due to the damage to the electronic components 117. Also, as shown in FIG. 24, a step portion of approximately 0.5 mm to 1.0 mm extending downward or horizontally may be formed out of the panel FPC board 104 having a thickness of approximately 0.2 mm by manually bending the panel FPC board 104. In such a case, however, there are the problems of variations of the position and the shape of the step, and disconnection might be caused. It is also possible to form a step portion out of the panel FPC board 104 with a jig. In this case, however, as the panel FPC board 104 returns to the original shape because of the elasticity, the electronic components 117 are easily damaged, and defective display is caused due to the damage to the electronic components 117.
In the above described liquid crystal display unit disclosed in Japanese Patent Publication No. 3322629, the flexible printed circuit board extends outside the front case and the rear case, at the height of the glass substrate. Therefore, like the conventional LCD unit 120 illustrated in FIGS. 20 through 23, when the liquid crystal display unit is housed inside a mobile phone handset including the upper chassis 150 having a protruding inner face portion, the electronic components attached to the flexible printed circuit board easily come into contact with the inner face of the upper chassis 150. Because of this, the structure disclosed in Japanese Patent Publication No. 3322629 also has the problem that the electronic components are easily damaged.
In the conventional LCD unit 120 illustrated in FIGS. 20 through 23, the driver IC 116 is not attached to the panel FPC board 104, but to the surface of the glass substrate 114 constituting the display panel. Accordingly, the panel FPC board 104 can be made smaller. However, the upper face of the driver IC 116 faces the lower face of the upper face portion 101b of the metal upper frame 101, and therefore, the upper face of the driver IC 116 easily comes into contact with the facing portion of the lower face of the upper face portion 101b of the metal upper frame 101 due to impact or vibration. As a result, the driver IC (an electronic component) 116 is often damaged, and the problem of defective display is caused by the damage to the driver IC (an electronic component) 116.